Epi-LASIK is a newer laser eye surgery procedure that has been developed to counteract the pit falls that you may find in the procedures lasik and lasek. Epi lasik is similar to these procedures but uses aspects of both at the same time which removes some disadvantages that may be associated with either of the operations.
LASIK involves cutting a flap in the cornea called the epithelium with a sharp blade or a laser whilst retaining some of the outer layer attached creating a flap like effect in which the surgeon can get to the naked eye, the surgery does run the risk of cutting too deep into the outer layer however recent advances in technology are making this mistake more unlikely.
Also instead of the alcohol that is used in LASEK to weaken the epithelial sheet, in Epi-LASIK the surgeon typically uses the plastic blade, called an epithelial separator, to separate the top layer from the eye. This avoids the possibility of a reaction from the alcohol, which can be harmful to epithelial cells.